/**
 * Created with Intellij IDEA.
 * Description;
 * User:墨琦
 * Data:2023-03-13
 * Time:17:28
 */
public class main2 {
    public static void main(String[] args) {
        int[] array= new int[]{1,2,3,3,5,5,2,8,1};
        int dog=0;
        for (int i = 0; i < array.length; i++)
        {
            dog ^= array[i];
        }
        System.out.println(dog);
    }
}
